/*
Copyright (c) 2001, Dr Martin Porter
Copyright (c) 2004,2005, Richard Boulton
All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:

  1. Redistributions of source code must retain the above copyright notice,
     this list of conditions and the following disclaimer.
  2. Redistributions in binary form must reproduce the above copyright notice,
     this list of conditions and the following disclaimer in the documentation
     and/or other materials provided with the distribution.
  3. Neither the name of the Snowball project nor the names of its contributors
     may be used to endorse or promote products derived from this software
     without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
package org.tartarus.snowball;
import java.lang.reflect.InvocationTargetException;
import java.io.Serializable;
public class SnowballProgram implements Serializable{
	protected SnowballProgram(){
		current=new StringBuilder();
		init();
	}
	static final long serialVersionUID=2016072500L;
	private void init(){
		cursor=0;
		limit=current.length();
		limit_backward=0;
		bra=cursor;
		ket=limit;
	}
	/**
	 * Set the current string.
	 * @param value current string
	 */
	public void setCurrent(String value){
		// Make a new StringBuilder.  If we reuse the old one, and a user of
		// the library keeps a reference to the buffer returned (for example,
		// by converting it to a String in a way which doesn't force a copy),
		// the buffer size will not decrease, and we will risk wasting a large
		// amount of memory.
		// Thanks to Wolfram Esser for spotting this problem.
		current=new StringBuilder(value);
		init();
	}
	/**
	 * Get the current string.
	 * @return  the current string
	 */
	public String getCurrent(){
		return current.toString();
	}
	// current string
	protected StringBuilder current;
	protected int cursor;
	protected int limit;
	protected int limit_backward;
	protected int bra;
	protected int ket;
	public SnowballProgram(SnowballProgram other){
		current=other.current;
		cursor=other.cursor;
		limit=other.limit;
		limit_backward=other.limit_backward;
		bra=other.bra;
		ket=other.ket;
	}
	protected void copy_from(SnowballProgram other){
		current=other.current;
		cursor=other.cursor;
		limit=other.limit;
		limit_backward=other.limit_backward;
		bra=other.bra;
		ket=other.ket;
	}
	protected boolean in_grouping(char[] s,int min,int max){
		if(cursor>=limit){
			return false;
		}
		char ch=current.charAt(cursor);
		if(ch>max||ch<min){
			return false;
		}
		ch-=min;
		if((s[ch>>3]&(0X1<<(ch&0X7)))==0){
			return false;
		}
		cursor++;
		return true;
	}
	protected boolean in_grouping_b(char[] s,int min,int max){
		if(cursor<=limit_backward){
			return false;
		}
		char ch=current.charAt(cursor-1);
		if(ch>max||ch<min){
			return false;
		}
		ch-=min;
		if((s[ch>>3]&(0X1<<(ch&0X7)))==0){
			return false;
		}
		cursor--;
		return true;
	}
	protected boolean out_grouping(char[] s,int min,int max){
		if(cursor>=limit){
			return false;
		}
		char ch=current.charAt(cursor);
		if(ch>max||ch<min){
			cursor++;
			return true;
		}
		ch-=min;
		if((s[ch>>3]&(0X1<<(ch&0X7)))==0){
			cursor++;
			return true;
		}
		return false;
	}
	protected boolean out_grouping_b(char[] s,int min,int max){
		if(cursor<=limit_backward){
			return false;
		}
		char ch=current.charAt(cursor-1);
		if(ch>max||ch<min){
			cursor--;
			return true;
		}
		ch-=min;
		if((s[ch>>3]&(0X1<<(ch&0X7)))==0){
			cursor--;
			return true;
		}
		return false;
	}
	protected boolean eq_s(CharSequence s){
		if(limit-cursor<s.length()){
			return false;
		}
		int i;
		for(i=0;i!=s.length();i++){
			if(current.charAt(cursor+i)!=s.charAt(i)){
				return false;
			}
		}
		cursor+=s.length();
		return true;
	}
	protected boolean eq_s_b(CharSequence s){
		if(cursor-limit_backward<s.length()){
			return false;
		}
		int i;
		for(i=0;i!=s.length();i++){
			if(current.charAt(cursor-s.length()+i)!=s.charAt(i)){
				return false;
			}
		}
		cursor-=s.length();
		return true;
	}
	protected int find_among(Among v[]){
		int i=0;
		int j=v.length;
		int c=cursor;
		int l=limit;
		int common_i=0;
		int common_j=0;
		boolean first_key_inspected=false;
		while(true){
			int k=i+((j-i)>>1);
			int diff=0;
			int common=common_i<common_j?common_i:common_j; // smaller
			Among w=v[k];
			int i2;
			for(i2=common;i2<w.s.length;i2++){
				if(c+common==l){
					diff=-1;
					break;
				}
				diff=current.charAt(c+common)-w.s[i2];
				if(diff!=0){
					break;
				}
				common++;
			}
			if(diff<0){
				j=k;
				common_j=common;
			}else{
				i=k;
				common_i=common;
			}
			if(j-i<=1){
				if(i>0){
					break; // v->s has been inspected
				}
				if(j==i){
					break; // only one item in v
				}
				// - but now we need to go round once more to get
				// v->s inspected. This looks messy, but is actually
				// the optimal approach.
				if(first_key_inspected){
					break;
				}
				first_key_inspected=true;
			}
		}
		while(true){
			Among w=v[i];
			if(common_i>=w.s.length){
				cursor=c+w.s.length;
				if(w.method==null){
					return w.result;
				}
				boolean res;
				try{
					Object resobj=w.method.invoke(this);
					res=resobj.toString().equals("true");
				}catch(InvocationTargetException e){
					res=false;
					// FIXME - debug message
				}catch(IllegalAccessException e){
					res=false;
					// FIXME - debug message
				}
				cursor=c+w.s.length;
				if(res){
					return w.result;
				}
			}
			i=w.substring_i;
			if(i<0){
				return 0;
			}
		}
	}
	// find_among_b is for backwards processing. Same comments apply
	protected int find_among_b(Among v[]){
		int i=0;
		int j=v.length;
		int c=cursor;
		int lb=limit_backward;
		int common_i=0;
		int common_j=0;
		boolean first_key_inspected=false;
		while(true){
			int k=i+((j-i)>>1);
			int diff=0;
			int common=common_i<common_j?common_i:common_j;
			Among w=v[k];
			int i2;
			for(i2=w.s.length-1-common;i2>=0;i2--){
				if(c-common==lb){
					diff=-1;
					break;
				}
				diff=current.charAt(c-1-common)-w.s[i2];
				if(diff!=0){
					break;
				}
				common++;
			}
			if(diff<0){
				j=k;
				common_j=common;
			}else{
				i=k;
				common_i=common;
			}
			if(j-i<=1){
				if(i>0){
					break;
				}
				if(j==i){
					break;
				}
				if(first_key_inspected){
					break;
				}
				first_key_inspected=true;
			}
		}
		while(true){
			Among w=v[i];
			if(common_i>=w.s.length){
				cursor=c-w.s.length;
				if(w.method==null){
					return w.result;
				}
				boolean res;
				try{
					Object resobj=w.method.invoke(this);
					res=resobj.toString().equals("true");
				}catch(InvocationTargetException e){
					res=false;
					// FIXME - debug message
				}catch(IllegalAccessException e){
					res=false;
					// FIXME - debug message
				}
				cursor=c-w.s.length;
				if(res){
					return w.result;
				}
			}
			i=w.substring_i;
			if(i<0){
				return 0;
			}
		}
	}

	/* to replace chars between c_bra and c_ket in current by the
     * chars in s.
	 */
	protected int replace_s(int c_bra,int c_ket,String s){
		int adjustment=s.length()-(c_ket-c_bra);
		current.replace(c_bra,c_ket,s);
		limit+=adjustment;
		if(cursor>=c_ket){
			cursor+=adjustment;
		}else if(cursor>c_bra){
			cursor=c_bra;
		}
		return adjustment;
	}
	protected void slice_check(){
		if(bra<0
				||bra>ket
				||ket>limit
				||limit>current.length()) // this line could be removed
		{
			System.err.println("faulty slice operation");
			// FIXME: report error somehow.
			/*
	    fprintf(stderr, "faulty slice operation:\n");
	    debug(z, -1, 0);
	    exit(1);
			 */
		}
	}
	protected void slice_from(String s){
		slice_check();
		replace_s(bra,ket,s);
	}
	protected void slice_from(CharSequence s){
		slice_from(s.toString());
	}
	protected void slice_del(){
		slice_from("");
	}
	protected void insert(int c_bra,int c_ket,String s){
		int adjustment=replace_s(c_bra,c_ket,s);
		if(c_bra<=bra){
			bra+=adjustment;
		}
		if(c_bra<=ket){
			ket+=adjustment;
		}
	}
	protected void insert(int c_bra,int c_ket,CharSequence s){
		insert(c_bra,c_ket,s.toString());
	}

	/* Copy the slice into the supplied StringBuilder */
	protected void slice_to(StringBuilder s){
		slice_check();
		s.replace(0,s.length(),current.substring(bra,ket));
	}
	protected void assign_to(StringBuilder s){
		s.replace(0,s.length(),current.substring(0,limit));
	}

	/*
extern void debug(struct SN_env * z, int number, int line_count)
{   int i;
    int limit = SIZE(z->p);
    //if (number >= 0) printf("%3d (line %4d): '", number, line_count);
    if (number >= 0) printf("%3d (line %4d): [%d]'", number, line_count,limit);
    for (i = 0; i <= limit; i++)
    {   if (z->lb == i) printf("{");
        if (z->bra == i) printf("[");
        if (z->c == i) printf("|");
        if (z->ket == i) printf("]");
        if (z->l == i) printf("}");
        if (i < limit)
        {   int ch = z->p[i];
            if (ch == 0) ch = '#';
            printf("%c", ch);
        }
    }
    printf("'\n");
}
	 */
};
